Extremely versatile, works in a lot of cirucmstances, very few situations where it does not work. Only downsides are that it can make heavy use of your RAM, particularly when downloading large files, and that when a download fails it doesn't have an in-add-on option to retry the download; in some circumstances I've found the download can be restarted using firefox's own download UI. Haven't needed to use other video downloading tools since I installed it - if this can't do it, I doubt anything can.